Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GELS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed1993

An evaluation of a new gel system (ID-gel) for antibody screening and identification.

An evaluation of the new "ID-Gel System" (Diamed) for the detection of red cell antibody-antigen reactions was undertaken in the King Khalid University Hospital Blood Bank. Antibody screening was performed in 700 patient samples using both the conventional test tube (bovine albumin and LISS) techniques and the new ID-gel technique. The results obtained were as follows: a) 70 antibodies of various types were detected by the bovine albumin technique. b) 98 antibodies were spotted by LISS. c) The ID-gel system detected 122 antibodies (17.43%) which included all those detected by the other two techniques. It was concluded that the ID-gel system is a far more sensitive technique than the conventional Blood Bank immuno-haematological tests. In addition, the ID-system has the further advantage of standardization of the test, shorter incubation time, no washing procedure and reduces the technologist time, effort and perhaps number.

Blood Grouping and Crossmatching↗
PubMed1998

A comparison of three preinduction cervical priming methods: prostaglandin E2 gel, Dilapan S rods and Estradiol gel.

The aim of the study was to evaluate the efficacy of three cervical priming methods. From January 1, 1994 to December 31, 1996 247 patients presenting an indication for induction of labor with an unripe cervix were randomly assigned to one of the following preinduction protocols: 0.5 mg of Prostaglandin E2 gel administered intracervically (n = 83), four hygroscopic Dilapan S rods applied intracervically (n = 82), and 150 mg of Estradiol gel administered intravaginally (n = 82). The inclusion criteria were the patient's informed consent, singleton pregnancy of more than 36 weeks, cephalic presentation, Bishop score < 5 points and reactive non-stress test. If the cervical maturation (Bishop score > or = 5, and/or Bishop score augmentation by 2 points) did not occur after 14 hours of priming, the case was considered a failure. In the opposite case the patient was induced by means of extraamniotic PGE2 administration. The mean gain in the Bishop score was 3.7 points in the PGE2 group 3.9 points in the Dilapan S group, and 2.8 points in the Estradiol group. 71 patients (85.5%) were successfully preinduced in the PGE2 group, 73 (89.0%) in the Dilapan S group, and 63 (76.8%) in the Estradiol group. Labor was induced by preinduction only in 23 patients (31.3%) of the PGE2 group in 17 (20.7%) of the Dilapan S group, and in 14 (17.1%) of the Estradiol group. The mean induction to delivery interval was 7 h 27 min in PGE2 group, 7 h 49 min in the Dilapan S group and 9 h 15 min in the Estradiol group. The Caesarean section rate was 24.4% in the PGE2 group, 10.5% in the Dilapan S group, and 24.4% in the Estradiol group. PGE2 gel and Dilapan S rods proved higher efficacy than Estradiol gel. The highest frequency of labor induced by preinduction only was in the PGE2 group. There were shorter induction to delivery intervals in the PGE2, and Dilapan S groups. The lowest Caesarean section rate was in the Dilapan S group. Neither serious side effects nor negative neonatal outcome were noted in either group.

Adult↗
PubMed1995

Dispersion coefficients of a protein and DNA fragment in polyacrylamide gel electrophoresis as a function of parameters defining the effective gel pore size and particle size.

The dispersion coefficient, D', of the representative homogeneous protein, conalbumin, decreases linearly as the polyacrylamide concentration increases from 4 to 14%T (2%C), and varies in a biphasic fashion as %C (Bis) is increased from 2 to 20%, with a broad peak between 5 and 15%C. D' increases linearly with the concentration of the initiator, potassium persulfate, in the range of 0.01-0.15%. D' remains constant when the field strength is varied from 5 to 15 V/cm. A DNA fragment (1857 bp) exhibits a constant D' in 4-6% polyacrylamide (2%C) at a field strength of 1 V/cm, and a linearly increasing D' at 5 V/cm, in analogy to its previously observed behavior in agarose gels. In solutions of uncrosslinked polyacrylamide, the decrease of the D' of conalbumin with polymer concentration is not significantly different from that in 2% N, N'-methylenebisacrylamide-crosslinked gels in the range of 4-14%T, while the decrease of mobility with polyacrylamide concentration is much steeper in 2% crosslinked compared to uncrosslinked polymer. Finally, delta (log D')/ delta T was found to be proportional to the retardation coefficient, KR (= -delta (log mu)/ delta T), in polyacrylamide gels. The ratio of -delta (log D')/ delta T over KR increases with field strength in the range of 5-15 V/cm.

Conalbumin↗
PubMed1984

Detection of iron-sulfur center-containing subunits of mitochondrial NADH dehydrogenase by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by high-performance gel permeation chromatography.

Soluble NADH dehydrogenase resolved from Complex I of the mitochondrial electron-transfer chain was subjected to gel electrophoresis in the presence of sodium dodecyl sulfate at 4 degrees C, and then the gel was stained for iron with bathophenanthroline disulfonate and thioglycolic acid. The 23,000-dalton subunit was markedly stained, and the 51,000-dalton subunit was also stained, but only slightly. High-performance gel permeation chromatography using an eluant containing 0.1% sodium dodecyl sulfate also demonstrated that these subunits contain an iron-sulfur center: the elution pattern recorded by light absorption at 400 nm gave two peaks corresponding to the positions of the subunits.

Animals↗
PubMed1984

Determination of placental alkaline phosphatase phenotypes by starch-gel and acrylamide gel electrophoresis.

The polymorphism of placental alkaline phosphatase (ALP) is usually studied by butanol extraction followed by starch gel electrophoretic separation at two different pH's, 8.6 and 6.0. Acrylamide gel electrophoresis (7.5%) in the presence of Triton X-100 is shown to be preferable in speed, reliability and reproducibility of results. All the placental ALP phenotypes detected had the same molecular mass by gradient acrylamide electrophoresis. The enzyme butanol extract is not sufficiently pure to enable the different placental ALP's to be distinguished by isoelectric focusing on polyacrylamide gels.

Alkaline Phosphatase↗
PubMed1987

High-performance gel permeation chromatography of glycosaminoglycans. Column calibration by gel electrophoresis.

High-performance gel permeation chromatography and sensitivity-enhanced polyacrylamide gel electrophoresis (SE-PAGE) have been combined to investigate the chromatographic properties of structurally related glycosaminoglycans. Enzymatically digested samples of hyaluronate, chondroitin 4-sulfate and dermatan sulfate were fractionated on a column series of TSK G4000SW and TSK G2000SW, eluted with 0.15 M sodium chloride. Isolated fractions were subjected to sensitivity-enhanced polyacrylamide gel electrophoresis for determination of molecular weight. These procedures allowed the rapid development of column calibration profiles for each glycosaminoglycan, under a given set of chromatographic conditions. The profiles obtained in 0.15 M sodium chloride yielded the following data: (1) at equal degrees of polymerization, hyaluronic acid chains have an apparently smaller hydrodynamic radius than the sulfated polymers, and (2) at equal molecular weights, all three glycosaminoglycans have approximately equal hydrodynamic radii.

Chromatography, Gel↗
PubMed1988

Preparation of metallothionein from rat liver and studies of its properties with respect to use as a standard in gel permeation chromatography, polyacrylamide gel systems, autoradiography and Western blotting.

1. A simple method for preparation of metallothionein (Mt) I and II has been developed for the purpose of making standards for use in various biochemical systems and in antibody production. 2. The theoretical content of SH groups in a Mt protein; assuming the mol. wt to be 10,000 and each molecule to contain 20 SH groups was found to be 7.1 and 7.7 times higher than for our purified Mt I and II, respectively. 3. In our native polyacrylamide gel system Mt I ran ahead of Mt II, while the two Mt forms were not separated in the Laemmli SDS system in which it behaved as a protein with mol. wt 10,000. In both gel systems, however, Mt I stained as a very faint band in comparison to Mt II, despite equal absorbance at 254 nm and Cd binding capacity. 4. Compared to staining of polyacrylamide gels with Coomassie Brilliant Blue less than 1/50 parts (1 ng) of the protein could be easily seen after silver staining. 5. It was found that Mt may undergo spontaneous modification, polymerization and loss of metal binding properties. 6. Spontaneous modification and polymerization reduced the antigenic properties of our purified Mt. Only Mt II appeared to be immunologically active.

Animals↗
PubMed1989

Human milk proteins: separation of whey proteins and their analysis by polyacrylamide gel electrophoresis, fast protein liquid chromatography (FPLC) gel filtration, and anion-exchange chromatography.

Human milk proteins are of nutritional and physiological significance to the newborn infant. To further study these proteins, a rapid procedure to separate and analyze human milk whey proteins was developed using fast protein liquid chromatography (FPLC). First, to separate whey proteins from casein, different variables such as low- or high-speed centrifugation at different temperatures with or without adjustment of pH to 4.6 or 4.3 and with or without addition of calcium to whole milk or skim milk were tested. Each variable was evaluated by gel filtration, anion-exchange chromatography, sodium dodecyl sulphate (SDS)-polyacrylamide gradient gel electrophoresis, immunoelectrophoresis, and immunodiffusion. The optimum method for a discrete separation of whey and casein is the adjustment of whole milk to pH 4.3 with addition of 60 mmol calcium/L, followed by ultracentrifugation. Rapid and sensitive separation and analysis of whey proteins was achieved by FPLC gel filtration and anion-exchange chromatography.

Chromatography, Gel↗
PubMed1999

Improvements in gel composition and electrophoretic conditions for broad-range mutation analysis by denaturing gradient gel electrophoresis.

Denaturing gradient gel electrophoresis (DGGE) is believed to be the most powerful pre-screening method for mutation detection currently available, being used mostly on an exon-by-exon basis. Broad-range DGGE for the analysis of multiple fragments or an entire gene is rarely applied. We and others have already shown that one or two DGGE conditions are usually sufficient to analyse an entire gene. Conditions, however, have never been profoundly tested and compared with alternative methods suggested in the literature. Trying to do so in this study, we found significant differences between the various gel systems. The optimal conditions we found for broad-range DGGE include 9% polyacrylamide for the gel, a denaturing gradient with a difference of 30-50% between the lowest and the highest concentration of denaturant, and electrophoresis in 0.5x TAE buffer at a voltage >100 V and <200 V.

Acrylic Resins↗
PubMed1981

Gel electrophoresis and gel chromatography of calf thymus histones in the presence of a cationic surfactant.

Five histone molecular species, H1, H2A, H2B, H3, and H4, of calf thymus were subjected to gel electrophoresis and gel chromatography in the presence of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and their behavior was compared with that in the presence of an anionic surfactant, sodium dodecyl sulfate (SDS). In the presence of CTAB, the retardation coefficient (KR) and distribution coefficient (Kd) values calculated for the five histone species were linearly related to their molecular weights, without showing abnormality of the type found in the presence of SDS. It was concluded that CTAB-gel electrophoresis is useful for the analysis of histones.

Animals↗
PubMed1994

Isolation and characterization by immunofluorescence, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot, restriction fragment length polymorphism-PCR, 16S rRNA gene sequencing, and pulsed-field gel electrophoresis of Rochalimaea quintana from a patient with bacillary angiomatosis.

Rochalimaea quintana was isolated from the blood of a French human immunodeficiency virus-infected patient with bacillary angiomatosis. The isolate showed the typical growth characteristics of Rochalimaea species and was inert when typical biochemical testing was used. The purpose of the present work was to characterize and compare this new isolate with reference strains of R. quintana, Rochalimaea vinsonii, and Rochalimaea henselae by using immunofluorescence, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot (immunoblot), restriction fragment length polymorphism-PCR of the citrate synthase gene, 16S rRNA gene sequencing, and pulsed-field gel electrophoresis. SDS-PAGE, Western blot, restriction fragment length polymorphism-PCR with TaqI enzyme, and 16S rRNA gene sequencing could differentiate the three Rochalimaea species and allowed characterization of the French isolate as R. quintana. However, identification of the Rochalimaea isolate to the species level was more easily obtained by immunofluorescence with specific murine antisera. Pulsed-field gel electrophoresis allowed differentiation of the French R. quintana isolate from R. quintana Fuller and may serve as an epidemiological tool.

AIDS-Related Opportunistic Infections↗
PubMed1999

Identification of proteins from two-dimensional gel electrophoresis of human erythroleukemia cells using capillary high performance liquid chromatography/electrospray-ion trap-reflectron time-of-flight mass spectrometry with two-dimensional topographic map analysis of in-gel tryptic digest products.

Protein spots from two-dimensional (2-D) gel electrophoresis of a human erythroleukemia cell line have been identified by analysis of the in-gel tryptic digests using capillary high performance liquid chromatography (HPLC) separation with on-line detection using electrospray ionization mass spectrometry (ESI-MS). This is performed using an electrospray/ion trap storage/reflectron time-of-flight mass spectrometer system (ESI-IT-reTOFMS). A 2-D topographic mapping display developed to process the on-line data acquired with this TOF system has been used to obtain mass identification of each peptide, even though the capillary HPLC only provides limited separation capability of the tryptic peptide mixtures studied herein. Using this method, a substantial fraction of the protein sequence can be covered and identified using the tryptic map. It is demonstrated that by entering the cell species, the approximate MW and pI range as determined by 2-D gel electrophoresis, and the tryptic peptide map into the database a unique match for identification of the protein generally results. It is also demonstrated that a much improved coverage of the protein sequence is obtained by this method relative to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS).

Amino Acid Sequence↗
PubMed2000

An exactly solvable Ogston model of gel electrophoresis. V. Attractive gel-analyte interactions and their effects on the Ferguson plot.

We examine the effect of attractive analyte-gel interactions within the framework of our recently developed lattice model of gel electrophoresis. We show that it is possible to take into account such interactions and still calculate exact mobilities for various analytes and gel structures. Our study then focuses on two main issues: (i) the effect of these interactions on the separation efficiency of the Ogston regime; and (ii) the presence of inflection points (changes of curvature) in Ferguson plots. We establish some general principles, and we describe the results for selected two- and three-dimensional model systems. Numerous practical problems, such as chiral separations and affinity electrophoresis, can be treated using this approach.

Chemical Phenomena↗
PubMed2000

Towards high performance two-dimensional gel electrophoresis using ultrazoom gels.

Proteomics is the analysis of protein expression in cells or tissues, e.g., to study cellular processes at the molecular level. Ultimately, a proteome analysis should encompass most if not all protein species in a biological sample, including those present in low copy numbers. We are developing two-dimensional gel electrophoresis technology by applying narrow pH range ultrazoom gels to enhance resolution and to improve the detection of low abundance proteins. Ultrazoom gels in the acidic pH range allow the detection of proteins down to 300 copies per cell of a B-lymphoma cell line. Protein separation in the alkaline pH range, however, still requires optimization, especially in conjunction with high sample loads.

Coloring Agents↗
PubMed1994

REF52 on Global Gel Navigator: an internet-accessible two-dimensional gel electrophoresis database.

Until recently, the REF52 2-D gel database of experiments with rat cell lines was accessible only with special software. This database has now been made available to all investigators with access to the Internet, using the World Wide Web (WWW) technology. The package which delivers the database through the WWW has been named the Global Gel Navigator and can be used to explore the data by several methods, including the direct selection of proteins in the displayed gel using the mouse.

Animals↗
PubMed1996

pH gradient electrophoresis of basic ribonucleases in sealed slab polyacrylamide gels: detection and inhibition of enzyme activity in the gel.

A simple method for the separation and specific detection of basic ribonucleases (RNases) was developed. The separation was achieved by polyacrylamide gel electrophoresis in a pH gradient generated by a carrier ampholyte (Pharmalyte 8-10.5) and arginine. In order to prevent interference from atmospheric carbon dioxide, the pH gradient was formed in sealed vertical gel slab. Human nonsecretory-type RNase, bovine pancreatic RNase A, and other basic proteins could be resolved without expensive equipment or complicated procedures. For activity detection after electrophoresis a zymogram technique was applied, using dry agarose film containing ethidium bromide plus RNA as substrate. This approach affords two advantages: (i) Basic RNase activities can be detected within 15 min, even in crude materials. The sensitivity is better than 0.5 ng of purified human nonsecretory-type RNase. (ii) An inhibition test of RNase activities in the gel, using human placental-type RNase inhibitor, can be performed.

Alkalies↗
PubMed1998

Routine identification of proteins from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels or polyvinyl difluoride membranes using matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS).

As the resource laboratory for Rockefeller University our emphasis continues to be on methodology development for the routine analysis of low abundance proteins isolated from native sources. In the past ten years, gel electrophoresis of proteins has become the method of choice for the preparation of microgram and submicrogram quantities of protein for primary structural characterization, and over 95% of the samples submitted for protein identification are either in a gel or bound to polyvinyl difluoride membranes (PVDF). As such, we employ multiple microanalytical approaches encompassing Edman sequence degradation, amino acid and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometric analysis to provide an integrated protein characterization of such samples. Here we describe the two major services we employ when providing protein identification from in-gel or PVDF-bound proteins.

Amino Acid Sequence↗
PubMed1995

Simple technique for the preparation of silicone gel particles: the effect of silicone gel particles on oxidative responses of macrophages.

A simple technique was developed to prepare phagocytosable-size particles from the silicone gel used in breast implants. Sonication of silicone gel (1 g) in 5 ml of 20 mM sodium phosphate buffer (pH 7.2) containing 1% (wt/vol) polyoxypropylene-polyethylene block surfactant (F-68 or F-108) produced silicone gel particles ranging from 1-50 microns in diameter. Passage of the suspension through a series of filters yielded phagocytosable particles (1-5 microns in diameter) at a concentration of ca. 2 x 10(9) particles/ml. The particles remained as individual particles, did not coalesce to form large clumps, and were not pelleted by centrifugation (2000 x g, 20 min). They were not toxic for rabbit alveolar macrophages (AM) during 24 h of incubation at 37 degrees C, did not elicit an oxidative burst from AM in vitro in a luminol-enhanced chemiluminescent assay, and did not significantly increase the phorbol myristate acetate (PMA)-elicited oxidative burst by AM. AM isolated from rabbits 2 days after the intravenous injection of silicone particles were not primed or activated (i.e., the AM did not show an enhanced oxidative burst when elicited with PMA in vitro). However, AM isolated from rabbits 2 days after intratracheal injection of the particles were primed but only exhibited a 4-6-fold increase in the oxidative burst elicited with PMA.

Animals↗